/*
 * Copyright 2024 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.springframework.data.jpa.repository.query;

import java.util.List;

import org.antlr.v4.runtime.tree.ParseTree;

import org.springframework.lang.Nullable;

/**
 * Interface defining an introspector for String-queries providing details about the primary table alias, the primary
 * selection projection and whether the query makes use of constructor expressions.
 *
 * @author Mark Paluch
 */
interface ParsedQueryIntrospector {

	/**
	 * Visit the parsed tree to introspect the AST tree.
	 *
	 * @param tree
	 * @return
	 */
	Void visit(ParseTree tree);

	/**
	 * Primary table alias. Contains the first table name/table alias in case multiple tables are specified in the query.
	 *
	 * @return
	 */
	@Nullable
	String getAlias();

	/**
	 * @return the primary selection.
	 */
	List<QueryToken> getProjection();

	/**
	 * @return {@code true} if the query uses a constructor expression.
	 */
	boolean hasConstructorExpression();
}
